Re: [PATCH v9 05/43] x86/compressed/64: Detect/setup SEV/SME features earlier in boot

From: Borislav Petkov <bp@alien8.de>
To: Michael Roth <michael.roth@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
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	Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
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	brijesh.ksingh@gmail.com, tony.luck@intel.com,
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Subject: Re: [PATCH v9 05/43] x86/compressed/64: Detect/setup SEV/SME features earlier in boot
Date: Wed, 2 Feb 2022 07:09:24 +0100	[thread overview]
Message-ID: <YfogFFOoHvCV+/2Y@zn.tnic> (raw)
In-Reply-To: <20220202005212.a3fnn6i76ko6u6t5@amd.com>

On Tue, Feb 01, 2022 at 06:52:12PM -0600, Michael Roth wrote:
> Since the kernel proper rdmsr()/wrmsr() definitions are getting pulled in via
> misc.h, I have to use a different name to avoid compiler errors. For now I've
> gone with rd_msr()/wr_msr(), but no problem changing those if needed.

Does that fix it too?

diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 16ed360b6692..346c46d072c8 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -21,7 +21,6 @@
 
 #include <linux/linkage.h>
 #include <linux/screen_info.h>
-#include <linux/elf.h>
 #include <linux/io.h>
 #include <asm/page.h>
 #include <asm/boot.h>
---

This is exactly what I mean with a multi-year effort of untangling what
has been mindlessly mixed in over the years...

> Since the rd_msr/wr_msr are oneliners, it seemed like it might be a
> little cleaner to just define them in boot/msr.h as static inline and
> include them directly as part of the header.

Ok, that's fine too.

> Here's what it looks like on top of this tree, and roughly how I plan to
> split the patches for v10:
> 
> - define the rd_msr/wr_msr helpers
>   https://github.com/mdroth/linux/commit/982c6c5741478c8f634db8ac0ba36575b5eff946
> 
> - use the helpers in boot/compressed/sev.c and boot/cpucheck.c
>   https://github.com/mdroth/linux/commit/a16e11f727c01fc478d3b741e1bdd2fd44975d7c
> 
> For v10 though I'll likely just drop rd_sev_status_msr() completely and use
> rd_msr() directly.
> 
> Let me know if I should make any changes and I'll make sure to get those in for
> the next spin.

Yap, looks good.

Thanks for doing that!

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette
